129 research outputs found

    Oxidative degradation of some antibiotics by permanganate ion in alkaline medium: A kinetic and mechanistic approach

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    Purpose: To investigate the kinetics of oxidative removal of two β-lactam antibiotics (A), namely, ampicillin and flucloxacillin.Methods: In this study, permanganate ion (MnO4-) was used as an oxidant in an alkaline medium at fixed ionic strength of 0.1 mol dm-3 and a temperature of 298 K utilizing a spectrophotometric technique. The obtained oxidation products were characterized using spot tests and FT-IR spectra.Results: The stoichiometry of the reactions was 1:4 (A : MnO4-). The reactions were a first order credence in [MnO4-] and fractional-first order  kinetics in antibiotic and hydroxyl ion. Influence of ionic strength was successfully explored. Dependence of reaction rates on temperature was studied and the activation parameters were computed and discussed. A plausible mechanism for the oxidation reactions has been elucidated. A consistent rate-law expression was also derived.Conclusion: This study introduces a significant treatment method for antibiotic removal, thus helping to protect the environment and human health. Keywords: Permanganate, Antibiotics, Oxidative degradation, Kinetics, Mechanis

    Calcul de conséquences pour le test d'extension conservative dans un système pair-à-pair

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    National audienceDans un système d'inférence pair-à-pair (P2PIS), un pair étend sa base de connaissances (KB) avec celle des autres pairs afin d'utiliser leurs connaissances pour répondre aux requêtes qui lui sont posées. Toutefois, l'ex tension d'une KB n'est pas nécessairement conservative. Une extension conservative garantit que le sens d'une KB est le même lorsqu'elle est considérée seule ou avec son extension. En revanche, une extension non conservative peut changer radicalement le sens d'une KB au sein de la théorie résultante. Il est par conséquent crucial pour un pair de savoir si un P2PIS est une extension conservative de sa KB. En effet, si ce n'est pas le cas (i) ses utilisateurs n'ont plus la bonne interprétation de sa KB, donc des requêtes en termes de sa KB et des réponses à celles-ci et (ii) les connaissances qu'il fournit aux autres pairs ne sont pas celles escomptées. Cet article est le premier à s'intéresser à la notion d'ex tension conservative dans le cadre des P2PIS. Notre contribution est d'étudier théoriquement et algorithmiquement le problème de tester si un P2PIS propositionnel est une extension conservative d'un pair donnée. En particulier, nous recourons au calcul de conséquences afin de reformuler ce problème et d'´élaborer un algorithme décentralisé pour le résoudre

    Bidirectional quantum teleportation of even and odd coherent states through the multipartite Glauber coherent state: Theory and implementation

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    Quantum teleportation has become a fundamental building block of quantum technologies, playing a vital role in the development of quantum communication networks. Here, we present a bidirectional quantum teleportation (BQT) protocol that enables even and odd coherent states to be transmitted and reconstructed over arbitrary distances in two directions. To this end, we employ the multipartite Glauber coherent state, comprising the Greenberger-Horne-Zeilinger, ground and Werner states, as a quantum resource linking distant partners Alice and Bob. The pairwise entanglement existing in symmetric and antisymmetric multipartite coherent states is explored, and by controlling the overlap and number of probes constructing various types of quantum channels, the teleportation efficiency of teleported states in both directions may be maximized. Besides, Alice's and Bob's trigger phases are estimated to explore their roles in our protocol using two kinds of quantum statistical speed referred to as quantum Fisher information (QFI) and Hilbert-Schmidt speed (HSS). Specifically, we show that the lower bound of the statistical estimation error, quantified by QFI and HSS, corresponds to the highest fidelity from Alice to Bob and conversely from Bob to Alice, and that the choice of the pre-shared quantum channel has a critical role in achieving high BQT efficiency. Finally, we show how to implement the suggested scheme on current experimental tools, where Alice can transfer her even coherent state to Bob, and at the same time, Bob can transfer his odd coherent state to Alice

    Interest rates volatility and its consequences on stock returns: The case study from Amman Stock Exchange, Jordan

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    Abstract. This paper examines the special effects of interest rates on the stock market return by using monthly time series data for the economy of Jordan over the period of 2006 to 2016. An extensive variety of econometric procedures have been involved to analyze the relationship between the interest rate and stock market return. The study exposes a constant and significant long-run relationship between the variables. By using Cointegration methods the experimental in the long run represents that a one percent rise in interest rate causes (12.3459 %)reduction in market index. The assessed error correction coefficient highlight that (-0.678522) percent deviation of stock returns are corrected in the short run. Impulse response function of the study furthermore sustains the positive relationship between the variables. The result of Variance decompositions recommends that about (99.99705%) of the variation in stock market returns is referring to its own shock which denotes that stock market returns are mostly independent of the other variables in the structure. To go over the main points, Granger causality analysis yield that there is no presence of a unidirectional causality as of interest rate to the market index.Keywords. Stock market, Cointegration, Granger causality, Interest rate, ASE.JEL. E40, E43, G12

    Optimisation of the Filament Winding Approach Using a Newly Developed In-House Uncertainty Model

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    The device under investigation in this paper consists of a float used to capture tidal energy, which is tethered by multiple flexible cables to a large barge-like reactor. The proposed float is made of a continuously wound glass-reinforced composite shell with stainless steel bolting plates integrated into the float walls to allow the connection of 5 stainless steel cables. Numerical computations are required to assess whether a delamination of the composite layers in the float is likely. The manufacturing of the device has various potential uncertainties that should be investigated, such as the number of the plies, the bond strength between the composite layers, and the fibre orientations of the composite material relative to the applied load. This paper provides a multi-level strategy to optimise the composite float system, which is manufactured from glass-reinforced plastic (GRP). In contrast to previous publications on the topic, the current work uses an efficient link between ANSYS Workbench and MATLAB through an in-house code that has been developed over 3 years. This allowed the whole process to be fully automated and to reduce the time and cost of the simulations. Previously, ANSYS APDL was linked to MATLAB, but limitations in terms of the geometry and boundary conditions made it impractical when compared to ANSYS Workbench for the simulation of complex features. This makes the current approach unique and rare when compared to the published work in the field. This approach allows the use of a huge number of trials and is able to reduce the number of parameters to be studied by selecting the most sensitive ones. Additionally, the developed tools may be used for the efficient, robust optimisation of the proposed structure. The current study has focused on exploring the effects of the fibre orientations and the optimum number of plies on the overall performance of the structure

    Influence of Thermomechanical Treatment on the Mechanical Behavior of Protaper Gold versus Protaper Universal (A Finite Element Study)

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    AIM: To compare and evaluate the influence of thermomechanical treatment of Protaper Gold file versus Protaper Universal file during testing of bending and torsion using ï¬nite-element analysis. METHODS: Two nickel-titanium NiTi rotary ï¬les (ProTaper Gold and ProTaper Universal) were used in this study. The files were imaged using stereomicroscope to produce 3D models. The behaviour of the instrument during bending and torsion was numerically analysed in CAD/CAM software package. RESULTS: Under bending, ProTaper, Gold showed higher flexibility and flexural resistance than ProTaper Universal. The highest stress was related at the cutting edge of both files. While during testing of torsion, the maximum amount of stresses was related to the base of the flutes in both files. ProTaper Gold showed higher torsional resistance than the ProTaper Universal file. CONCLUSION: Thermomechanical treatment improved the mechanical response (bending and torsional resistance) of NiTi files

    Present and future of gait assessment in clinical practice: Towards the application of novel trends and technologies

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    BackgroundDespite being available for more than three decades, quantitative gait analysis remains largely associated with research institutions and not well leveraged in clinical settings. This is mostly due to the high cost/cumbersome equipment and complex protocols and data management/analysis associated with traditional gait labs, as well as the diverse training/experience and preference of clinical teams. Observational gait and qualitative scales continue to be predominantly used in clinics despite evidence of less efficacy of quantifying gait.Research objectiveThis study provides a scoping review of the status of clinical gait assessment, including shedding light on common gait pathologies, clinical parameters, indices, and scales. We also highlight novel state-of-the-art gait characterization and analysis approaches and the integration of commercially available wearable tools and technology and AI-driven computational platforms.MethodsA comprehensive literature search was conducted within PubMed, Web of Science, Medline, and ScienceDirect for all articles published until December 2021 using a set of keywords, including normal and pathological gait, gait parameters, gait assessment, gait analysis, wearable systems, inertial measurement units, accelerometer, gyroscope, magnetometer, insole sensors, electromyography sensors. Original articles that met the selection criteria were included.Results and significanceClinical gait analysis remains highly observational and is hence subjective and largely influenced by the observer's background and experience. Quantitative Instrumented gait analysis (IGA) has the capability of providing clinicians with accurate and reliable gait data for diagnosis and monitoring but is limited in clinical applicability mainly due to logistics. Rapidly emerging smart wearable technology, multi-modality, and sensor fusion approaches, as well as AI-driven computational platforms are increasingly commanding greater attention in gait assessment. These tools promise a paradigm shift in the quantification of gait in the clinic and beyond. On the other hand, standardization of clinical protocols and ensuring their feasibility to map the complex features of human gait and represent them meaningfully remain critical challenges

    A robust design of an innovative shaped rebar system using a novel uncertainty model

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    The current paper has investigated a newly developed re-bar system by implementing uncertainty models to optimise its geometry. The study of the design parameters of this re-bar system has been carried out utilising a novel uncertainty model that has been developed at Swansea University. The importance of this invention comes from the fact that the whole process of optimisation has been automated by linking ANSYS Workbench to MATLAB via the in-house written code, Despite the fact that in the past, ANSYS APDL was linked to MATLAB, however, the APDL was very limited to only simple geometries and boundary conditions unlike the Workbench which can simulate complex features. These shortfalls have been overcome by automating the process of optimisation, identifying the key influential parameters and the possibility to carry out a huge number of trials. Moreover, the tools that have been developed can pave the way for robust optimisation of this proposed structure. The uncertainty in the design parameters of this re-bar system is of a paramount importance in order to optimise the bond strength between the newly developed rebar and the concrete matrix as well as to fully understand the behaviour of the proposed system under pull-out conditions. The interface between the rebar and the concrete matrix was considered as a ‘cohesive zone’ whereby the interfacial area is studied as a function of the bonding strength

    A robust design of an innovative shaped rebar system using a novel uncertainty model

    Get PDF
    The current paper has investigated a newly developed re-bar system by implementing uncertainty models to optimise its geometry. The study of the design parameters of this re-bar system has been carried out utilising a novel uncertainty model that has been developed at Swansea University. The importance of this invention comes from the fact that the whole process of optimisation has been automated by linking ANSYS Workbench to MATLAB via the in-house written code, Despite the fact that in the past, ANSYS APDL was linked to MATLAB, however, the APDL was very limited to only simple geometries and boundary conditions unlike the Workbench which can simulate complex features. These shortfalls have been overcome by automating the process of optimisation, identifying the key influential parameters and the possibility to carry out a huge number of trials. Moreover, the tools that have been developed can pave the way for robust optimisation of this proposed structure. The uncertainty in the design parameters of this re-bar system is of a paramount importance in order to optimise the bond strength between the newly developed rebar and the concrete matrix as well as to fully understand the behaviour of the proposed system under pull-out conditions. The interface between the rebar and the concrete matrix was considered as a ‘cohesive zone’ whereby the interfacial area is studied as a function of the bonding strength
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